The present invention relates to functional assessment of renal artery stenosis, and more particularly, to non-invasive functional assessment of renal artery stenosis from medical image data and blood flow simulations.
Renal artery stenosis (RAS) is the narrowing of the renal artery. RAS can impede blood flow to the target kidney and may result in hypertension, atrophy of the affected kidney, and ultimately renal failure if not treated. Medical image based anatomical assessment of RAS is routinely done in clinical practice. A number of imaging modalities, including magnetic resonance imaging (MRI), computed tomography (CT), x-ray angiography, and ultrasound, are used for this purpose, and each of these imaging modalities provides some estimate of the anatomical narrowing of the renal artery due to the blockage. Nevertheless, the true hemodynamic significance of RAS cannot typically be assessed by merely estimating the anatomical narrowing of the renal artery. The hemodynamic significance of RAS can be determined using an invasive catheterization procedure to insert a pressure wire to measure the pressure drop across the stenosis. However, this procedure is not widely used for RAS, mostly due to the invasive nature of the procedure.
In recent years, large multi-center trials have demonstrated the drawbacks of using anatomical severity of the RAS of as the criterion for stenting. Studies have shown that the functional assessment of RAS is important for identifying patients who will benefit from stenting.